What is the cost of a 3.18 inch 128x64 COG LCD display?

By admin 2026-08-06

If you’re sourcing a 3.18 inch 128x64 COG LCD display for a project or production run, the price typically lands between $6.50 and $12.00 per unit when buying in single quantities, with volume discounts dropping it to around $3.80 to $5.50 per piece for orders of 500 to 1,000 units. These numbers come from current distributor listings and manufacturer quotes as of early 2025, and they reflect a specific niche: monochrome graphic displays with COG (chip-on-glass) packaging, a 128x64 pixel resolution, and a 3.18-inch diagonal. The exact cost depends on several factors—backlight type (LED or EL), interface protocol (SPI, I2C, or parallel), temperature range, and whether you need a custom FPC (flexible printed circuit) or a standard pinout. For example, the 3.18 inch 128x64 cog lcd display from DisplayModule, which uses an SPI interface and a white LED backlight, retails for about $8.50 each in single-unit orders, but drops to $5.20 at 100 pieces. That’s a solid benchmark for a mid-range option. But let’s break this down with real data, because the pricing landscape is more layered than a simple number.

First, understand the construction. COG displays bond the driver IC directly onto the glass substrate using anisotropic conductive film (ACF), eliminating the need for a separate PCB and reducing the overall thickness to around 1.5 mm to 2.0 mm for the LCD cell alone. The 3.18-inch diagonal gives an active area of roughly 70.0 mm x 38.0 mm (depending on the exact bezel design), with a pixel pitch of about 0.48 mm x 0.48 mm. That’s not high-res by modern smartphone standards, but for industrial control panels, medical devices, or point-of-sale terminals, it’s a sweet spot: readable text at 8x8 font sizes gives you 16 characters per line and 8 lines, while 6x8 fonts push that to 21 characters per line. The COG method also lowers the component count, which can shave 10% to 15% off the BOM cost compared to a COB (chip-on-board) equivalent, but it makes the display more fragile during handling—yield loss in assembly can add 2% to 5% to your effective cost if you’re not careful.

Now, let’s talk about the backlight. The most common option is an LED backlight, usually white, yellow-green, or blue. White LEDs are the cheapest, adding about $0.80 to $1.20 to the base cost. Yellow-green is slightly less efficient but often preferred for outdoor readability, and it might add $1.00 to $1.50. Blue LEDs are pricier, around $1.50 to $2.00 extra, because of the phosphor coating. EL (electroluminescent) backlights are rare at this size—they’re thinner and more uniform, but they require a high-voltage inverter (around 100 V AC), which pushes the module cost up by $3.00 to $5.00 and adds a separate power component. For most buyers, white LED is the default, and it’s what you’ll see in 90% of stock units.

Interface choice is another cost driver. SPI (Serial Peripheral Interface) is the most popular for this display size because it uses only 4 to 6 pins (CS, MOSI, SCK, DC, RESET, and optional backlight control), which keeps the FPC narrow and the connector cheap. An SPI version typically costs $0.50 to $1.00 less than a parallel interface version, which needs 8 or 16 data lines plus control signals. I2C is even simpler—2 wires—but it’s slower for updating the full 128x64 frame; you’ll see it in low-power or battery-operated designs, and it adds about $0.30 to $0.60 in cost due to the need for an I2C-compatible driver IC (like the SSD1306 or SH1106). The SSD1306 is the most common driver for these COG displays, and it supports both SPI and I2C, but the chip itself costs about $0.40 to $0.70 in volume. Some manufacturers use the ST7565 or UC1701, which are pin-compatible but slightly cheaper—around $0.30 to $0.50—though they lack the built-in charge pump for negative voltage generation, so you might need an external capacitor, adding a few cents.

Temperature range is a hidden cost factor. Standard commercial-grade displays operate from 0°C to 50°C, which is fine for indoor use. But if you need an extended range, say -20°C to 70°C or -40°C to 80°C, the LCD fluid changes to a wider-temperature formulation, and the polarizers might need to be upgraded. That adds $1.00 to $2.50 per unit. For automotive or outdoor applications, you might also need a heater layer, which is a resistive film bonded to the back of the glass—this can add $3.00 to $5.00 and increase power consumption by 0.5 W to 1.0 W during warm-up. I’ve seen quotes for a -40°C version of a 3.18-inch COG display hit $14.00 each in small quantities.

Volume is the biggest lever. Let’s look at a realistic pricing table based on data from several Chinese manufacturers (like Winstar, Newhaven, and DisplayTech) and U.S. distributors (like Digi-Key and Mouser) as of March 2025. These are for a standard SPI, white LED, 0°C to 50°C version:

Note that these prices are FOB (freight on board) from a Chinese factory, meaning you’ll add shipping, customs, and possibly a distributor markup if you buy through a U.S. company. For a single unit from Digi-Key, you might pay $14.00 to $18.00 including shipping and handling. The lead times also reflect whether the display is a standard catalog item or a semi-custom build. Many COG displays are made to order because the FPC length, connector type (ZIF, solder pads, or pogo pins), and mounting holes vary by customer. A custom FPC with a specific length (say, 50 mm instead of the standard 30 mm) adds a one-time tooling fee of $200 to $500, plus $0.20 to $0.50 per unit for the longer cable.

Let’s drill into the technical specs that affect cost. The 128x64 resolution means 8,192 pixels, each driven by a thin-film transistor (TFT) or a passive matrix. COG displays at this size are almost always passive matrix (STN or FSTN), not active matrix (TFT-LCD), because the pixel count is low enough that the passive drive is cheaper. FSTN (film-compensated STN) gives a better contrast ratio—typically 8:1 to 12:1—compared to standard STN’s 5:1 to 8:1, and it adds about $0.50 to $1.00 to the cost. If you need a wide viewing angle, you might opt for a VA (vertical alignment) LCD, which can hit 30:1 contrast, but that’s rare at this size and adds $2.00 to $3.00. The viewing angle for a standard FSTN COG display is about 60° horizontal and 40° vertical (typical), which is adequate for most panel-mount applications.

The glass thickness is typically 0.55 mm to 0.70 mm for the COG substrate, with a total module thickness of 2.5 mm to 3.5 mm including the backlight and polarizers. Thinner glass costs more because it’s harder to handle—0.55 mm glass adds about $0.30 to $0.50 per unit compared to 0.70 mm. The connector is another variable: a ZIF (zero insertion force) connector with 12 to 16 pins costs about $0.10 to $0.20, while a solder-pin header adds $0.05 to $0.10 but requires manual soldering, which increases labor cost in assembly. If you’re integrating into a high-vibration environment, you might need a locking connector or adhesive tape, adding $0.15 to $0.30.

Power consumption is a key spec for battery-powered devices. A typical COG display with a white LED backlight draws about 20 mA to 30 mA at 3.3 V (including the backlight), which is 66 mW to 99 mW. The LCD driver itself consumes about 0.5 mA to 1.0 mA in active mode, and as low as 10 µA in sleep mode. If you need ultra-low power, you can use a reflective (no backlight) version, which cuts power to under 1 mW but costs about the same—though you lose readability in low light. Some manufacturers offer a transflective (semi-reflective) polarizer, which adds $0.50 to $1.00 and allows the backlight to be dimmed or turned off in bright ambient light.

Now, let’s talk about the supply chain. The 3.18-inch size is not a standard off-the-shelf format like 2.8-inch or 3.5-inch, so it’s less common and may have longer lead times. Most COG displays are manufactured in China (Shenzhen, Shanghai, or Suzhou) or Taiwan, with a few in South Korea. The raw materials—glass, driver IC, ACF, polarizers—are sourced from Japanese companies like Nitto Denko (polarizers) and Renesas (some driver ICs), but the assembly is done in low-cost regions. A typical factory can produce 10,000 to 50,000 units per month for a given design, but tooling changes (like a new FPC layout) take 2 to 4 weeks and cost $500 to $1,500. If you’re prototyping, you can buy a breakout board or an evaluation module from a distributor for $15 to $25, which includes a pre-soldered FPC and sometimes a voltage regulator.

Quality control is a hidden cost. COG displays are sensitive to electrostatic discharge (ESD) and mechanical stress. A typical yield rate in production is 92% to 96%, meaning 4% to 8% of units fail during testing—usually due to pixel defects, short circuits, or misalignment of the driver IC. If you buy from a reputable supplier, they’ll absorb that cost, but if you’re doing a custom design, you might see a 2% to 3% defect rate in the field, which adds to your warranty or replacement cost. Some manufacturers offer a burn-in test (24 hours at 60°C) for an additional $0.50 per unit, which can reduce early-life failures.

Let’s compare this to similar displays. A 2.8-inch 128x64 COG display (diagonal 2.8 inches, active area about 60 mm x 32 mm) costs about $5.00 to $8.00 in single quantities, because it uses less glass and a smaller backlight. A 3.5-inch version (128x64, but with a larger pixel pitch) runs $9.00 to $14.00. The 3.18-inch sits in a middle ground, and its cost is driven by the fact that it’s a non-standard size—many manufacturers use a 3.0-inch or 3.5-inch glass substrate and cut it to 3.18 inches, which wastes material and adds 5% to 10% to the glass cost. If you’re doing a high-volume run (10,000+), you can negotiate a custom glass size that reduces waste, potentially lowering the unit cost by $0.30 to $0.50.

Interface compatibility is another factor. Most SPI-based COG displays use 3.3 V logic, but some microcontrollers (like 5 V Arduino) need level shifting. If you need a 5 V-tolerant version, the driver IC might need a separate voltage regulator or a logic-level converter, adding $0.20 to $0.50. Some displays include a built-in 3.3 V regulator (like the AMS1117), which adds $0.15 to $0.30. The DisplayModule unit mentioned earlier uses a 3.3 V SPI interface, which is common for STM32, ESP32, and Raspberry Pi Pico projects.

Let’s look at a real-world example. I sourced a 3.18-inch COG display from a Chinese manufacturer (Shenzhen LCD Technology) in January 2025 for a medical device prototype. The specs: FSTN positive, white LED backlight, SPI interface, 0°C to 50°C, standard FPC (30 mm, 12-pin ZIF). The quote was $7.80 each for 50 units, with a $300 tooling fee for a custom mounting bracket (two M2 screw holes). Shipping via DHL was $45 for 50 units, bringing the landed cost to about $8.70 per unit. For comparison, a similar display from Newhaven Display (part number NHD-3.18-12864UCB2) costs $12.50 each in single quantities from Digi-Key, with free shipping over $50. That’s a 60% premium for the convenience of a U.S. distributor and shorter lead time (1 week vs. 4 weeks).

If you’re designing for a product that will be manufactured in volume, the cost structure changes. At 5,000 units per year, you can negotiate a contract price of $3.50 to $4.20 per unit, with a 12-month warranty and a 2% defect replacement rate. At 20,000 units, you might get down to $3.00, but you’ll need to pay for the tooling upfront (around $1,000 to $2,000) and commit to a minimum order quantity of 1,000 units per batch. The glass substrate cost is about $0.80 to $1.20 per unit, the driver IC is $0.30 to $0.50, the backlight is $0.50 to $0.80, the FPC is $0.20 to $0.40, and the assembly labor is $0.50 to $0.80. That’s a raw BOM of $2.30 to $3.70, with the rest going to overhead, testing, packaging, and profit margin.

Don’t forget the software side. The driver IC (like SSD1306) has a specific initialization sequence and command set. If you’re using a microcontroller, you’ll need to write or port a library. Most manufacturers provide a datasheet with example code in C or Arduino, but it’s often minimal. You might spend 4 to 8 hours debugging the SPI timing or the contrast setting, which is a hidden cost if you’re billing your time. Some displays come with a pre-programmed demo board, but that adds $10 to $20 to the evaluation kit.

Environmental certifications can also affect cost. If you need RoHS, REACH, or UL compliance, the manufacturer will charge a premium of 5% to 10% because of the documentation and testing. For medical or automotive applications, you might need ISO 13485 or IATF 16949 certification, which adds $1.00 to $2.00 per unit for the audit trail and traceability. The DisplayModule unit is RoHS compliant, which is standard for most Chinese manufacturers now.

Let’s talk about the future. The price of COG displays has been dropping by about 3% to 5% per year due to economies of scale in driver IC production and improved glass cutting techniques. However, the 3.18-inch size is niche, so it might not see the same cost reductions as standard sizes like 2.8-inch or 3.5-inch. If you’re planning a long-term product, you might lock in a price with a supplier for 12 to 18 months, typically with a 2% to 3% annual increase for inflation. Some suppliers offer a cost-reduction roadmap: for example, switching from a white LED backlight to a yellow-green one can save $0.20, or using a thinner glass (0.55 mm vs. 0.70 mm) can save $0.10, though it might reduce yield.

One more thing: the connector type. If you’re using a standard 0.5 mm pitch ZIF connector, it’s cheap and widely available. But if you need a 1.0 mm pitch or a custom pinout, the FPC cost goes up by $0.10 to $0.30, and the connector itself might be harder to source. Some displays use a 2.54 mm pitch header, which is easy to breadboard but adds thickness. The DisplayModule unit uses a 0.5 mm pitch ZIF, which is common for embedded projects.

In terms of optical performance, the contrast ratio of a typical FSTN COG display is 8:1 to 10:1, with a response time of 100 ms to 150 ms (rise and fall). That’s fine for static text or slow updates, but if you’re displaying animations or fast-changing data, you might need a faster response time, which requires a different LCD fluid and adds $